Introduction/Purpose: Triple arthrodesis is commonly used to correct severe or rigid progressive collapsing foot deformity (PCFD). In many cases of PCFD, patients have associated first tarsometatarsal instability demonstrated by plantar gapping or dorsal subluxation on the lateral weight-bearing radiographs. During flatfoot reconstruction this is usually addressed with a first tarsometatarsal fusion to realign the joint and to restore the medial column height. However in the setting of triple arthrodesis it has not been well established if it is necessary to add a first tarsometatarsal fusion to the procedure in order to adequately correct the overall deformity. This study retrospectively examined pre- and post-operative radiographs of patients that had first tarsometatarsal instability as a component of their PCFD and who were managed by triple arthrodesis alone. Methods: All triple arthrodesis cases were searched for a single surgeon between 2013 and 2021. Inclusion criteria were patients who had a diagnosis of PCFD and had an isolated triple arthrodesis without first tarsometatarsal joint fusion. Pre-operative radiographs were then examined for the presence of first tarsometatarsal joint instability on the lateral weight-bearing view only. This was demonstrated by either plantar gapping or first metatarsal dorsal subluxation at the tarsometatarsal joint. Those patients who were a minimum of 21 months post-op were called to obtain current radiographs. Measurement of the sagittal first metatarsal-medial cuneiform angle as well as a the first metatarsal lift as described by King and Toolan (FAI 2004) was performed. Results: Twenty patients satisfied the inclusion criteria and were included in the study. Of these patients, five had no correction of their first tarsometatarsal joint instability postoperatively and were considered failures. The remaining fifteen patients demonstrated early correction of their first tarsometatarsal joint instability and were called back for longer term follow-up radiographs. Average follow-up was 4.8 years (range 1.8 - 9.4 years). The sagittal first metatarsal-medial cuneiform angle (plantar gapping) improved significantly from 3.8 degrees to 1.0 degrees (p=0.00002). The first metatarsal lift (dorsal subluxation) corrected from 4.0 mm to 1.5 mm (p=0.000001). Only one patient showed radiographic evidence of arthritis in the first tarsometatarsal joint at final follow-up. Conclusion: First tarsometatarsal joint fusion to correct medial column instability is well established in flatfoot reconstruction cases. However less is known about whether this is required when performing a triple arthrodesis for PCFD. In this study, 75% of patients had their first tarsometatarsal joint instability correct itself after isolated triple arthrodesis and maintained this correction at 4.8 year follow-up. In many cases of PCFD with medial column instability, triple arthrodesis alone may be adequate to restore overall alignment thereby avoiding the additional operative time and risk for complication associated with a first tarsometatarsal joint fusion. First tarsometatarsal joint instability correction following isolated triple arthrodesis. Pre-operative radiographs demonstrate plantar gapping and dorsal subluxation at the first tarsometatarsal joint consistent with medial column instability. At 2.8 year post-operative follow up after isolated triple arthrodesis, radiographs show maintained correction of the instability.

Background: Triple arthrodesis is commonly used to correct rigid progressive collapsing foot deformity (PCFD). These patients often have associated first tarsometatarsal (TMT) instability on lateral weightbearing radiographs. It has not been well established if it is necessary to add first TMT arthrodesis to adequately correct the overall deformity. This study retrospectively examined pre- and postoperative radiographs of PCFD patients with first TMT instability that were managed by triple arthrodesis alone. Methods: All triple arthrodesis cases were searched for a single surgeon between 2013 and 2021. Inclusion criteria were patients with PCFD who underwent triple arthrodesis without first TMT joint fusion. Preoperative radiographs were examined for first TMT joint instability, demonstrated by plantar gapping of the first metatarsal-medial cuneiform angle or first metatarsal dorsal subluxation at the TMT joint. Measurement of sagittal first metatarsal-medial cuneiform angle and first metatarsal subluxation as described by King and Toolan was performed. Results: Twenty patients satisfied the inclusion criteria. Six patients did not demonstrate at least 30% improvement of one or both measurements of first TMT instability postoperatively and were considered failures. Fourteen patients demonstrated correction of their first TMT joint instability. Average follow-up was 5.0 (range, 1.8-9.4) years. The first metatarsal-medial cuneiform angle improved from 3.8 to 1.1 degrees ( P < .05). The first metatarsal subluxation corrected from 4.1 to 1.5 mm ( P < .05). One patient showed radiographic evidence of arthritis in the first TMT joint at final follow-up. Conclusion: Seventy percent of patients with PCFD with asymptomatic first TMT joint instability demonstrated correction of first TMT radiographic instability with isolated triple arthrodesis. This was maintained at 5-year mean follow-up. In cases of PCFD with medial column instability, triple arthrodesis alone may be adequate to restore overall alignment.

Background: Particulated autograft cartilage implantation is a surgical technique that has been previously described for the repair of osteochondral lesions of the talus (OLT). It uses cartilage fragments harvested from the OLT that are minced into 1-2-mm3 fragments and then immediately reimplanted back into the chondral defect and sealed with fibrin glue during a single-stage surgery. The purpose of this study was to characterize the suitability of these minced cartilage fragments as immediate autograft for the treatment of OLTs. Methods: Thirty-one patients undergoing primary arthroscopic surgery for their OLT consented to have their loose or damaged cartilage fragments removed and analyzed in the laboratory. Harvested specimens were minced into 1- to 2-mm3 fragments and cell count, cell density, and cell viability were determined. In addition, physical characteristics of the OLT lesion were recorded intraoperatively and analyzed including size, location, Outerbridge chondromalacia grade of the surrounding cartilage, density of underlying bone, and whether the surgeon thought the OLT was primarily hyaline or fibrocartilage. Results: An average of 419 000 cells was able to be obtained from the harvested OLT fragments. The cells were 71.2% viable after mincing. Specimens from younger patients and from lesions with worse chondromalacia adjacent to the OLT had significantly higher cell numbers. Those from lateral lesions and with worse neighboring chondromalacia had a significantly higher cell density. None of the remaining physical OLT characteristics studied seemed to significantly affect cell number or viability. Conclusion: A large number of viable cells are available for immediate autografting by removing the loose or damaged cartilage from an OLT and mincing it into 1- to 2-mm3 fragments. These can be reimplanted into the chondral defect in a single-stage surgery. Future clinical studies are needed to determine if the addition of these live autologous cells either alone or in conjunction with other techniques significantly improves the quality of the repair tissue and clinical outcomes. Level of Evidence: Level IV, case series.

Category: Basic Sciences/Biologics; Arthroscopy Introduction/Purpose: Osteochondral lesions of the talus (OLT) are frequently treated with microfracture and may be augmented with decellularized extracellular matrix or particulated juvenile cartilage. The damaged OLT cartilage is often discarded. Infrequently it is used as a source for autologous chondrocyte expansion and implantation in a subsequent procedure. This resected cartilage has demonstrated variable chondrocyte viability. The influence of cartilage type on chondrocyte viability, whether frayed fibrocartilage from in vivo repair or delaminated hyaline cartilage, remains unknown. Also, little has been reported on the use of the OLT cartilage as a source for immediate cartilage autograft. The purpose of this study is to evaluate chondrocyte quantity and viability from the excised cartilage of OLTs at the time of arthroscopic debridement and microfracture. Methods: Patients aged 18 to 65 undergoing arthroscopic debridement and microfracture of talar OLTs were included. IRB approval of the study protocol was obtained. At the time of ankle arthroscopy, the cartilage from the OLT was collected either by GraftNet™ Autologous tissue collector (GraftNet™ Autologous Tissue Collector, Arthrex; Naples, FL) or manual collection and mincing of the specimen with a scalpel. Chondrocytes were isolated by overnight digestion with 2% collagenase in tissue culture medium at 37°C. The isolated cells were stained with Trypan Blue and counted for total cell number and viability (%), using an automated cell counter. Data collection included patient age, size and location of the OLT, intraoperative surgeon assessment of cartilage type (hyaline cartilage, fibrocartilage, or mixed fibro-hyaline cartilage), histologic determination of cartilage type, weight of the specimen, and chondrocyte cell count and viability. Results: Fourteen OLT specimens were collected. The average size was 0.831 (SD ± 1.10) cm 2 , and average weight 0.19 (SD ± 0.17) grams. Overall, the average number of chondrocytes was 1.12 x106 (SD ± 1.13 x106) cells/mm 2 and 3.99 x106 (SD ± 3.28 x106) cells/gram. The average viability was 72.36% (SD ± 12.25%). Using histologic determination of cartilage type, in hyaline specimens (n = 8, 57.14%) we found 1.08 x106 (SD ± 0.85 x106) chondrocytes/cm 2 , 70.73% (SD ± 11.73 %) viability. In fibrocartilage specimens (n = 2, 14.29%) we found 0.37 x106 (SD ± 0.10 x106) chondrocytes/cm 2 , 78.08% (SD ± 22.03%) viability. In mixed cartilage specimens (n = 4, 28.57%) we found 1.58 x106 (SD ± 1.80 x106) cells/cm 2 , 72.78% (SD ± 11.79%) viability. (Table 1) Conclusion: We found OLT chondrocyte viability of 72.36%, with a trend toward greater chondrocyte concentration and similar viability comparing hyaline and fibro cartilage, respectively. Cartilage type was consistent between intraoperative and histologic assessment in all but four specimens. OLT cartilage has the potential to serve as an immediate intraoperative chondrocyte autograft source for enhancement of talus cartilage repair procedures, eliminating the risk of donor site morbidity and additional surgeries as in culture-based methods. Further study with more patients may shed light on the accuracy of intraoperative cartilage classification, and differences in chondrocyte quantity and viability between cartilage types.

Category: Ankle; Ankle Arthritis Introduction/ Purpose: With the increased utilization of total ankle arthroplasty (TAA) for the treatment of end-stage ankle arthritis, the effect of joint line level on patient outcomes remains unclear. It has previously been demonstrated that patients with end-stage ankle arthritis have an elevated joint line level compared with nonarthritic ankles, and the joint line post-TAA remains elevated compared with nonarthritic ankles. The objectives of this study were to (1) Propose a reliable radiographic method to measure the ankle joint line level that can be applied both pre- and postoperatively following TAA and (2) Determine the effect of joint line level alterations in relation to tibiotalar range of motion (ROM) following TAA. Methods: A retrospective review was performed on patients who underwent a TAA at a single institution between January 2018 to April 2021. Inclusion criteria required patients to have a minimum of one-year postoperative follow-up with preoperative weight-bearing anteroposterior (AP) radiographs and postoperative weight-bearing AP and lateral flexion-extension ROM radiographs. Patients with concomitant procedures affecting ROM were excluded. Radiographic joint line and ROM measurements were performed by two observers. The proposed joint line measuring technique computes four joint line measurements for each AP radiograph- high, low, center of the talus, and center of the axis (Figure 1). Paired T-tests, Student T-tests, Chi-Square tests, univariable and multivariable regression models, and Spearman Correlation Coefficients were computed. The ankles were divided into two cohorts for subanalyses- lowered versus elevated joint line. Intra-class correlation coefficients (ICC) were calculated to assess inter-observer reliability. A probability of 0.05 or less was considered significant for all analyses. Results: A total of 33 patients were included with 17(51.5%) valgus-aligned ankles and 16(48.5%) varus ankles. The average postoperative tibiotalar ROM was 6.7°(±7.1°) dorsiflexion to 21.7°(±8.3°) plantarflexion. 22 patients had a lowered joint line compared to 11 patients with an elevated joint line (2.2±1.25mm lowered versus 1.9±1.2mm elevated; p< 0.0001). Of the four joint line measurements, three(high, center, axis) demonstrated a significant positive correlation between lowering the joint line and improved tibiotalar dorsiflexion and total ROM (all p< 0.05). Plantarflexion was not significantly affected by joint line alterations. Compared to patients with an elevated joint, patients with a lowered joint line had improved tibiotalar dorsiflexion (8.8° versus 2.5°; p=0.0015) and total ROM (31.0° versus 22.9°; p=0.0191), respectively. The inter-rater reliability was nearly perfect, ranging from ICC=0.96-0.99. Conclusion: Lowering the tibiotalar joint line level may more closely reestablish the native tibiotalar joint line and results in improved tibiotalar dorsiflexion and total ROM following TAA. This evidence may refute the concern that “overstuffing” the joint decreases postoperative ROM.

BACKGROUND:Minimally invasive surgery for the treatment of hallux valgus deformities has become increasingly popular. Knowledge of the location of the hallux metatarsophalangeal (MTP) proximal capsular origin on the metatarsal neck is essential for surgeons in planning and executing extracapsular corrective osteotomies. A cadaveric study was undertaken to further study this anatomic relationship.METHODS:Ten nonpaired fresh-frozen frozen cadaveric specimens were used for this study. Careful dissection was performed, and the capsular origin of the hallux MTP joint was measured from the central portion of the metatarsal head in the medial, lateral, dorsal, plantarmedial, and plantarlateral dimensions.RESULTS:The ten specimens had a mean age of 77 years, with 5 female and 5 male. The mean distances from the central hallux metatarsal head to the MTP capsular origin were 15.2 mm dorsally, 8.4 mm medially, 9.6 mm laterally, 19.3 mm plantarmedially, and 21.0 mm plantarlaterally.CONCLUSION:The MTP capsular origin at the hallux metatarsal varies at different anatomic positions. Knowledge of this capsular anatomy is critical for orthopaedic surgeons when planning and performing minimally invasive distal metatarsal osteotomies for the correction of hallux valgus.TYPE OF STUDY:Cadaveric Study.

Category: Basic Sciences/Biologics; Hindfoot Introduction/Purpose: Current understanding of the kinematics of the transverse tarsal joint continues to evolve. Unfortunately, most prior studies have been in cadavers or under non-physiologic conditions. Weight bearing CT scans may provide more accurate in vivo information about the position of the transverse tarsal joint during eversion and inversion. Methods: Institutional Review Board approval was obtained. Five normal volunteers underwent bilateral weight bearing cone- beam PedCAT scans (CurveBeam LLC, Hatfield, PA) while standing on platforms that positioned both hindfeet in 20o of valgus and then 20o of varus. The CT scans had a field-of-view diameter of 350 mm and a field-of-view height of 200 mm. The scan exposure time was 9 seconds, with a total scan time of 54 seconds. The datasets were reconstructed using filtered back projection with 0.37mm isotropic voxels. The resulting volumes were then segmented, identifying the [x, y, z] coordinates that comprised each bone. Each bone of the hindfoot was segmented on the scan images and the motion between the talus and calcaneus was analyzed. A similar analysis was done for motion between the navicular and cuboid. Two-tailed paired Student's t- tests were used to compare the angle and distance measurements between valgus and varus positions. Results: In the coronal plane, the axis of the talus rotated by 17.0° relative to the axis of the calcaneus as the hindfoot moved from eversion to inversion (p=0.03). The distance between the centers of the talar head and the anterior calcaneus also moved closer to each other by 7.1 mm (p=0.00005). There was no significant change in angle or distance between the navicular and cuboid when moving from eversion to inversion. The angle between the navicular and cuboid axes changed 2.1° (p=0.7), while the distance changed 0.8 mm (p=0.7) Conclusion: Previous work proposed that the transverse tarsal joint locking mechanism occurs from the talonavicular and calcaneocuboid joint axes diverging (less parallel) as the hindfoot inverts. The current weight bearing CT data shows that not only do the talar and calcaneal axes rotate relative to each other during inversion, but the center of the talar head and anterior calcaneus translate to move closer together. Because the navicular and cuboid do not move, transverse tarsal joint locking may occur due to tightening of the joint capsules and ligaments. Further in vivo study is warranted, especially under dynamic weightbearing conditions.

BACKGROUND:Surgeons frequently add an Achilles tendon lengthening or gastrocnemius recession to increase dorsiflexion following total ankle replacement. Previous studies have looked at the effects of these procedures on total tibiopedal motion. However, tibiopedal motion includes motion of the midfoot and hindfoot as well as the ankle replacement. The current study examined the effects of Achilles tendon lengthening and gastrocnemius recession on radiographic tibiotalar motion at the level of the prosthesis only.METHODS:Fifty-four patients with an average of 25 months follow-up after total ankle replacement were divided into 3 groups: (1) patients who underwent Achilles tendon lengthening, (2) patients who had a gastrocnemius recession, (3) patients with no lengthening procedure. Tibiotalar range of motion was measured on lateral dorsiflexion-plantarflexion radiographs using reference lines on the surface of the implants.RESULTS:Both Achilles tendon lengthening and gastrocnemius recession significantly increased tibiotalar dorsiflexion when compared to the group without lengthening. However, the total tibiotalar range of motion among the 3 groups was the same. Interestingly, the Achilles tendon lengthening group lost 11.7 degrees of plantarflexion compared to the group without lengthening, which was significant.CONCLUSION:Both Achilles tendon lengthening and gastrocnemius recession increased radiographic tibiotalar dorsiflexion following arthroplasty. Achilles tendon lengthening had the unexpected effect of significantly decreasing plantarflexion. Gastrocnemius recession may be a better choice when faced with a tight ankle replacement because it increases dorsiflexion without a compensatory loss of plantarflexion.LEVEL OF EVIDENCE:Level III, retrospective comparative study.

Category: Bunion; Basic Sciences/Biologics Introduction/Purpose: Minimally-invasive surgery (MIS) for hallux valgus correction has become increasingly common. This technique involves an osteotomy of the first metatarsal, followed by fixation with two cannulated screws. Since screws are typically not bicortical, they rely upon bone quality within the metatarsal head for fixation strength. However, bone mineral density (BMD) within different regions of the metatarsal head is unknown. Measuring the BMD in the target region may predict the strength of the bone-screw fixation. Similar to previous work which determined the optimal position for lag screw placement in the femoral head during hip fracture fixation, this study aimed to determine average BMD within four quadrants of the metatarsal head using CT and thus predict the optimal trajectories for cannulated screws during the MIS bunion procedure. Methods: All patients between 18-75 years of age scheduled to undergo MIS hallux valgus correction by one of two surgeons experienced in the MIS technique were eligible to participate. Patients were excluded if they had a prior first metatarsal surgery, pre-existing hardware, previous first metatarsal fracture, or a history of osteoporosis treatment. Patients were enrolled prospectively, and a weight-bearing CT scan of the affected foot was obtained pre-operatively. Demographic factors including age, sex, laterality, body mass index (BMI), comorbidities, and smoking status as well as standard three-view weight-bearing radiographs were collected for all patients.Using the coronal CT slice at maximal metatarsal head diameter, each head was divided into equal quadrants. Hounsfield units (HU) within each quadrant were measured independently by three study investigators using our hospital’s radiology viewing software (Merge PACS; IBM Corporation, Armonk, NY), and these density measurements were averaged. Statistical analysis was conducted using ANOVA and Student’s t-test. Results: Fifteen patients were included for preliminary analysis. All patients were female. The average age was 45.7 years. 9 of the 15 included feet were right feet. Average BMI was 28.0. One patient reported active smoking prior to surgery. Comorbidities included obesity in three patients; none were diabetic. One had a history of diplegic cerebral palsy. The average HVA on a weight- bearing AP foot x-ray was 28.2°, and the average IMA was 12.6°. The BMD within the metatarsal head varied by quadrant, with the two combined dorsal quadrants having higher average BMD than the two combined plantar quadrants (122 vs 85 HU; p<0.001). The dorsal lateral quadrant had the highest average BMD of any quadrant (132 HU, p<0.001; Table 1). Conclusion: The density of the metatarsal head did vary by region within the head. The highest BMD was found in the dorsal lateral quadrant, and the lowest in the plantar lateral and plantar medial quadrants, which did not differ significantly from each other. Because strength of screw fixation is predicated upon screw design as well as bone density, these results suggest that surgeons may wish to direct screws toward the dorsolateral region of the metatarsal head in order to achieve optimal fixation. Further work is needed to determine whether this varies with patient age, gender, or hallux valgus angle.

Background: Charcot-Marie-Tooth (CMT) disease is a hereditary motor-sensory neuropathy that is often associated with a cavovarus foot deformity. Limited evidence exists for the orthopedic management of these patients. Our goal was to develop consensus guidelines based upon the clinical experiences and practices of an expert group of foot and ankle surgeons. Methods: Thirteen experienced, board-certified orthopedic foot and ankle surgeons and a neurologist specializing in CMT disease convened at a 1-day meeting. The group discussed clinical and surgical considerations based upon existing literature and individual experience. After extensive debate, conclusion statements were deemed “consensus” if 85% of the group were in agreement and “unanimous” if 100% were in support. Conclusions: The group defined consensus terminology, agreed upon standardized templates for history and physical examination, and recommended a comprehensive approach to surgery. Early in the course of the disease, an orthopedic foot and ankle surgeon should be part of the care team. This consensus statement by a team of experienced orthopedic foot and ankle surgeons provides a comprehensive approach to the management of CMT cavovarus deformity. Level of Evidence: Level V, expert opinion.

Painful accessory navicular and spring ligament injuries in athletes are different entities from more common posterior tibialis tendon problems seen in older individuals. These injuries typically affect running and jumping athletes, causing medial arch pain and in severe cases a pes planus deformity. Diagnosis requires a detailed physical examination, standing radiographs, and MRI. Initial treatment focuses on rest, immobilization, and restriction from sports. Orthotic insoles may alleviate minor pain, but many patients need surgery to expedite recovery and return to sports. The authors review their approach to these injuries and provide surgical tips along with expected rehabilitation to provide optimal outcomes.

BACKGROUND::Lateral hindfoot pain in patients with flatfoot deformity is frequently attributed to subfibular impingement. It remains unclear whether this is primarily due to bony or soft-tissue impingement. No studies have used weight-bearing CT scans to evaluate subfibular impingement.METHODS::Patients with posterior tibial tendonitis were retrospectively searched and reviewed. Subjects had documented flatfoot deformity, posterior tibial tenderness, weight-bearing plain radiographs, and a weight-bearing CT scan. CT scans were evaluated for calcaneofibular impingement on the coronal view and talocalcaneal impingement on the sagittal view. The distance between these structures was measured, along with the sinus tarsi volume. In the second part of this study, 6 normal volunteers underwent weight-bearing CT scans on a platform that held both feet in 20 degrees of varus, followed by 20 degrees of valgus. The same measurements were performed.RESULTS::Thirty-five percent of flatfoot patients with posterior tibial tendonitis had bony impingement between the fibula and calcaneus on the coronal view. Thirty-eight percent had bony impingement between the talus and calcaneus on the sagittal view. Subjects with bony impingement based on CT scan had significantly higher talonavicular abduction angles on plain radiographs than those without impingement. Sinus tarsi volume decreased by more than half when the subtalar joint moved from varus to valgus in normal controls.CONCLUSION::Bony subfibular impingement in patients with flatfeet was less common than previously reported. Accurate diagnosis of bony impingement may be useful for surgical decision-making.LEVEL OF EVIDENCE::Level III, retrospective comparative study.

BACKGROUND:Arthroscopy has been increasingly used to evaluate small joints in the foot and ankle. In the hallux metatarsophalangeal (MTP) joint, little data exist evaluating the efficacy of arthroscopy to visualize the articular surface. The goal of this cadaveric study was to determine how much articular surface of the MTP joint could be visualized during joint arthroscopy.METHODS:Ten fresh cadaveric foot specimens were evaluated using standard arthroscopy techniques. The edges of the visualized joint surface were marked with curettes and Kirschner wires; the joints were then surgically exposed and imaged. The visualized surface area was measured using ImageJ® software.RESULTS:On the distal 2-dimensional projection of the joint surface, an average 57.5% (range, 49.6%-65.3%) of the metatarsal head and 100% (range, 100%-100%) of the proximal phalanx base were visualized. From a lateral view of the metatarsal head, an average 72 degrees (range, 65-80 degrees) was visualized out of an average total articular arc of 199 degrees (range, 192-206 degrees), for an average 36.5% (range, 32.2%-40.8%) of the articular arc.CONCLUSION:Complete visualization of the proximal phalanx base was obtained. Incomplete metatarsal head visualization was obtained, but this is limited by technique limitations that may not reflect clinical practice.CLINICAL RELEVANCE:This information helps to validate the utility of arthrosocpy at the hallux metatarsophalangeal joint.

Category: Ankle, Arthroscopy, Sports Introduction/Purpose: The surgical treatment of large or revision osteochondral (OCD) lesions of the talus remain challenging. Currently, there are several treatment options for these patients, including: osteochondral autograft (OATS), allograft cartilage extracellular matrix (Arthrex BioCartilage), and particulated juvenile articular cartilage allograft (Zimmer DeNovo). Due to the relative rarity of these procedures, the literature comparing these three modalities is scarce. The aim of this study was to assess midterm clinical outcomes after these surgical treatments for large or revision talar OCD lesions. Methods: Hospital IRB approval was obtained. We reviewed surgical case logs and identified 78 total patients between 2003- 2015 for inclusion in this retrospective study. Thirty-three patients were excluded due to incomplete preoperative or postoperative outcome scoring data, and 23 patients are pending followup, leaving a cohort of N = 22 patients (5 OATS, 5 DeNovo, 12 BioCartilage). Functional outcomes preoperatively and postoperatively were evaluated using Short Form 12-item Physical and Mental Health Survey (SF12 M and SF12P) and Foot Function Index (FFI) scores, ability to return to sport or work, and the need to return to the OR for revision surgery. Data were compared using paired student’s t-test and a one way ANOVA. Results: Mean age was 38y with mean followup of 4.3y (range 1.1-12.5). Of 22 patients, three were revisions. Mean lesion size was (12.6x9.1x6.5 mm). All groups showed significant improvements in FFI (p < 0.05) compared to preoperative baseline. Only the BioCartilage group showed significant improvement in SF12P (37.6 vs 47.8, p<0.05). The OATS and DeNovo groups did not show a significant increase in SF12P, and none of the groups demonstrated significant improvement in SF12 M. All patients returned to work, and 8/11 (73%) athletes returned to sport. There were no significant differences between groups when comparing SF12, FFI, and return to sport/work. Revision surgery was necessary in 6/22 (28%) patients. Post-hoc power analysis revealed limited power (0.23), and effect size (f=0.32) may be due to small sample size. Conclusion: All three treatment methods resulted in good medium-term functional results for the treatment of large or revision talar OCD lesions. However, we were unable to distinguish significant differences between OATS, Biocartilage, and Denovo, likely due to small cohort numbers and low power. Further study is warranted with increased patient numbers to improve power and differentiate among the three treatment options, as well as provide longer clinical and radiographic follow-up.

Category: Ankle, Ankle Arthritis, Sports Introduction/Purpose: Total ankle replacement (TAR) and ankle arthrodesis (AA) are two common surgical treatment modalities for end stage tibiotalar arthritis. A key deciding point between the two is anticipated functional outcome postoperatively, especially in regards to sports related activities. However, there is a paucity of data available to help advise patients in their decision making. While TAR provides a theoretical benefit of improved functionality, the outcomes of several European studies have shown mixed results. These studies are limited by small sample size, obsolete TAR implants not used in the United States, and nonspecific outcome measures. The purpose of this study was to compare postoperative sports activity levels following modern TAR and AA in a U.S. population, which may benefit surgical decision making and guide patient expectations. Methods: We conducted a retrospective comparative study that consisted of patients who underwent a TAR (N=62) or AA (N=51) between 2009-2015. The mean age of the arthrodesis group was 57.7 years ± 12.12 (28.84-85.26). There were 27 male participants and 24 female participants. The TAR group had 31 male and 31 female participants with a mean age of 64.9 years ± 8.57 (45-79.6). Exclusion criteria included paralysis, rheumatoid arthritis, revision surgery, incomplete pre- and post-operative scores, and follow up less than 2 years. General health and foot-ankle function were assessed using the SF-12 Health Survey and the revised Foot Function Index (FFI-R) preoperatively and at final follow-up. In addition, activity levels were assessed using a Return to Activities Following Surgery questionnaire that was administered at final follow up. This form included a Visual Analog Scale for Pain, satisfaction questions, and a list of 25 activities. Patients were asked to record their current level of activity, ability to participate pre- and post-surgery, and whether their desired level was met. All three measurements tools were compared between both treatment groups. Results: The SF-12 physical score both groups significantly increased postoperatively from 33.18 ± 10.37 to 43 ± 10.32 for AA’s and from 32.88 ± 9.44 to 45.81 ± 12.94 (p < 0.001) for TAR’s. The FFI scores showed a significant increase in both groups (p < 0.001). In the AA group, 88% of patients returned to work and would repeat the surgery, compared to 92% of patients in the TAR group. In terms of satisfaction and pain, the TAR group was more satisfied (1.78 vs. 1.44) and had less postoperative pain (1.32 vs. 2.56 p < 0.05). The AA group reported a significant increase in six activities including: golf (p < 0.05), weight lifting, and walking (p<0.001), while the TAR group reported significant increase in 15 activities, including hiking, tennis, and yoga (p<0.001). Conclusion: Our study revealed a significant increase in general physical function, foot function, and activity level in both groups. The TAR group was able to perform a wider range of activity and sports compared to the AA group. Overall, TAR patients were significantly more satisfied with their procedure compared to AA patients.

Category: Basic Sciences/Biologics, Hindfoot Introduction/Purpose: Sinus Tarsi syndrome is a frequent cause of anterolateral foot pain following injury. Chronic lateral subtalar pain, often referred to as “Sinus Tarsi Syndrome”, is commonly reported to occur following trauma. One hypothetical epidemiological predisposing factor for sinus tarsi syndrome is flatfoot deformity with valgus hind foot alignment. Common conservative treatment includes medial heel posting to attempt to widen the sinus tarsi space and alleviate synovitic pain. Although treatment with operative intervention has been reported, no data exists to evaluate if hindfoot realignment functionally opens the sinus tarsi volume. Methods: Weight-bearing Computed Tomography (CT) scans were obtained in 5 healthy volunteers standing at rest on slanted platforms, 25 degree valgus and 25 degree varus. The volume of the sinus tarsi was measured on each scan. Cross sectional area of the sinus tarsi was measured in 3.6 mm slices from the most lateral fully enclosed image to the most lateral aspect of the middle facet of the subtalar joint. Area measurements were multiplied by cut depth (3.6 mm) and summed. Critical angle distance was measured as a straight line from the most lateral point of the lateral process of the talus to the base of the critical angle of Gissane. Subfibular distance was then measured from the most distal tip of the fibula in a straight line to the nearest point of the lateral calcaneal wall. Data were compared using a one way ANOVA and Tukey’s multiple comparison test. Results: The mean sinus tarsi volume in the valgus position was 325.1 mm3 (±88) and 313.3 (±71) for the left and right foot, respectively. In the varus position, the mean sinus tarsi volume increased to 646.8 mm3 (±169) and 599 mm3 (±203). There was a significant difference between the varus and valgus position for both feet (left p<0.01 / right p<0.05). The critical angle distance increased from 28.1 mm (±7.5) to 91.3 mm (±26) for the left foot and 26.3 mm (±7.6) to 87 mm (±27.9) for the right foot when realigned to the varus position (p<0.0001). There was not a significant increase in the sub fibular distance when repositioned from valgus to varus (p=0.06 / p=0.35). Conclusion: This study confirms that moving from a valgus to a varus position significantly increases the volume of the sinus tarsi as well as significantly increases the distance from the lateral process of the talus to the calcaneal angle of Gissane. Interestingly, subfibular distance did not significantly increase, although this may reach significance with increased samples. With confirmation that adjusting hindfoot positioning impacts lateral osseous impingement, future studies are warranted to correlate these findings with clinical symptoms.

Category: Arthroscopy, Sports Introduction/Purpose: Tendoscopy is a relatively new method of evaluating for tendon lesions in foot and ankle surgery. Despite multiple studies describing peroneal tendoscopy use, no study exists to determine the efficacy of tendoscopy at visualizing the entire length of the peroneal tendons. The purpose of this cadaver study was to measure the length of the peroneal tendons that could be visualized using tendoscopy Methods: Ten (10) fresh cadaveric specimens, complete above- or through-knee specimens, were evaluated. Peroneal Tendoscopy was performed with routine portal placement including proximally 2 cm above the lateral malleolar tip and mid- tendon proximal to the peroneal tubercle. For the initial 5 specimens, the peroneus longus sheath was entered distal to the tendon bifurcation and proximal to the lateral cuboid under direct visualization for zone 3 tendoscopy. For the subsequent 5 specimens, a more distal point closer to the base of the 5th metatarsal was used as a landmark for skin incision and the sheath was entered at the distal aspect of the cuboid. The edges of visualized longus and brevis tendons were marked with kirschner wires placed through the tendon percutaneously under direct visualization. The tendon sheaths were then dissected and the distances from anatomic landmarks were directly measured. Results: Proximally (zone 1), both the peroneus tendons were followed circumferentially to the musculotendinous junction of the longus in all specimens. Peroneus brevis was visualized in zone 2 to an average of 19.5 mm (95% CI 16.5-22.5) from its insertion onto the base of the 5th metatarsal. Using a peroneal tubercle start point, zone 3 of peroneus longus was visualized up to an average of 17 mm (11-23) from its insertion onto the base of the 2nd metatarsal. Using a more distal start point, longus was seen up to 1.6 mm (0.3-2.9) from its insertion. The muscle belly of peroneus brevis ended an average of 1.9 mm (-3.7-7.3) above the tip of the lateral malleolus. Conclusion: The results suggest that the vast majority of the peroneal tendons can be visualized during peroneal tendoscopy. It was also noted that a more distal skin portal site may improve visualization of zone 3 of peroneus longus.

Category: Ankle, Ankle Arthritis, Hindfoot, Midfoot/Forefoot Introduction/Purpose: There has been in increased interest in foot and ankle arthritis in the literature in recent years. A significant focus of the literature has been which operative techniques are best for managing these problems. Some work has been done analogizing disability due to ankle arthritis to more familiar joints such as the hip. There is little data explaining how much patient reported disability is associated with each type of isolated foot and ankle arthritis. Various clinical rating scales have proven how debilitating foot and ankle arthritides can be to patients. The purpose of our study was to use Functional Foot Index (FFI) and Short Form-12 (SF-12) rating scales to compare the patient reported disability associated with ankle, hindfoot, midfoot, and hallux metatarsalphalangeal (MTP) arthritides. Methods: We retrospectively reviewed the FFI and SF-12 (both Physical Component Scores (PCS) and Mental Component Scores (MCS)) of patients who presented to a high volume orthopaedic foot and ankle practice between 2010 and 2016 with either ankle, hindfoot, midfoot or hallux MTP arthritis. We included patients between 18-65 years of age who underwent a surgical procedure for arthritis within 6 months of their initial presentation. We excluded patients with any medical or surgical co-morbidities known to affect disability scores. A total of 214 FFI and 195 SF-12 data sets were included. Results: Study population SF-12 PCS scores for all patients with ankle or foot arthritis were significantly lower than US age-based norms. Patients with ankle arthritis had the highest disability (FFI score 46.5, SF-12 PCS 32.3). Patients with midfoot and hindfoot arthritis had intermediate disability (Midfoot FFI score 34.9, SF-12 PCS 34.5; Hindfoot FFI score 44.3, SF-12 PCS 34.5). Patients with hallux MTP arthritis had the lowest disability (FFI score 32.9, SF-12 PCS 40.7). All FFI and SF-12 PCS scores were statistically significant. SF 12 MCS were not statistically significant. Conclusion: All patients with foot and ankle arthritis had increased disability compared to US age-based norms. Patients with ankle arthritis experience the most self-reported disability and patients with hallux MTP arthritis experience the least self- reported disability of the isolated types of arthritis in orthopaedic foot and ankle.